Fix the vertical navbar submenu painting over the footer dropdown

.changeset/navbar-footer-dropdown-overlap.md

@@ -0,0 +1,5 @@
+---
+"@tabler/core": patch
+---
+
+Fixed the vertical navbar submenu painting over the `.navbar-footer` user dropdown.

core/scss/layout/_navbar.scss

@@ -112,6 +112,7 @@
 
     .dropdown-menu {
       position: static;
+      z-index: auto;
       min-width: 0;
       padding: 0;
       margin: 0;
@@ -259,6 +260,7 @@
 
     .dropdown-menu {
       position: absolute;
+      z-index: $zindex-fixed;
       inset-inline-start: 100%;
       top: 0;
       min-width: var(--dropdown-min-width);